RFC: Sunsetting XRender backend

[Aleix Pol]

On Tue, Jun 8, 2021 at 5:39 PM Vlad Zahorodnii <vlad.zahorodnii at kde.org> wrote:
>
> Hi,
>
> The Xrender backend was added at the time when OpenGL drivers were not
> particularly known for being rock solid stable. So, having Xrender
> render backend as fallback did make a lot of sense back then. Nowadays
> though, it's not the case. OpenGL render backend has been the default
> one for many years. It's quite stable, and it allows implementing more
> features, e.g. wobbly windows effect, etc. Given that, the Xrender
> render backend is in a bitrotten state now. Many features are not tested
> with it; the only time when it gets noticed is when changes in other
> parts of kwin break build in the xrender backend.
>
> Another issue is that we would like to provide better integration
> between kwin's scene graph and qtquick's scene graph. QtQuick doesn't
> support and most likely will never support Xrender. This poses a problem
> as we would like to provide native thumbnail item support in qtquick and
> re-implement effects such as desktop grid and present windows using QML.
>
> Given the bitrotten state, our focus being shifted towards wayland, and
> no native Xrender support in qtquick, I propose to remove the xrender
> backend. Thoughts?
>
> Cheers,
> Vlad

+1 it will allow us to have more effective APIs.

Also what Martin Flöser said.

Aleix